package org.niux.aims.common.util;

import java.security.MessageDigest;

/**
 * 
 * <p>
 * Title:
 * </p>
 * 
 * <p>
 * Description:
 * </p>
 * 
 * <p>
 * Copyright: Copyright (c) 2003
 * </p>
 * 
 * <p>
 * Company:
 * </p>
 * 
 * @author unascribed
 * 
 * @version 1.0
 * 
 */

public class StringUtil {

	private final static String[] hexDigits = {

	"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

	/**
	 * 
	 * 转换字节数组为16进制字串
	 * 
	 * @param b
	 *            字节数组
	 * 
	 * @return 16进制字串
	 * 
	 */

	public static String byteArrayToHexString(byte[] b) {

		StringBuffer resultSb = new StringBuffer();

		for (int i = 0; i < b.length; i++) {

			resultSb.append(byteToHexString(b[i]));

		}

		return resultSb.toString();

	}

	private static String byteToHexString(byte b) {

		int n = b;

		if (n < 0)

			n = 256 + n;

		int d1 = n / 16;

		int d2 = n % 16;

		return hexDigits[d1] + hexDigits[d2];

	}

	public static String MD5Encode(String origin) {

		String resultString = null;

		try {

			resultString = new String(origin);

			MessageDigest md = MessageDigest.getInstance("MD5");

			resultString = byteArrayToHexString(md.digest(resultString.getBytes()));

		}

		catch (Exception ex) {

		}

		return resultString.substring(8, 28);

	}

	public static void main(String[] args) {

		System.err.println(MD5Encode("admin"));

	}

}
